Not only are both 'about' and 'to' grammatically correct but you could also say, 'There was a freshness in his work' as well.
There are minor differences in nuance in each of these sentences but which you choose is largely a matter of your personal speaking style.
As you are aware there are often many ways in English to say the same thing and still be grammatically correct. The best way to learn which are right and
which are not is by listening to the choices native speakers make and practicing what you hear in your own conversations.